1. Field of the Invention
The present invention relates to liquid cooling of memory modules installed in a computer system.
2. Background of the Related Art
Computer systems are being designed and built with an ever increasing number of heat generating components. Given the limited footprint of most computing systems, a continuous increase in the number of heat generating components creates challenging heat dissipation issues. If not dealt with adequately, the increasing amount of heat can harm the structural and data integrity of the computer system, making the effect felt both at a system and component level.
Most electronic packages or nodes in large computer environments are housed in a chassis that is disposed in a rack. Traditionally, these nodes have been cooled by forced air cooling using air moving devices, such as fans and blowers, selectively disposed somewhere in the environment as to allow optimum air flow. These air moving devices are often designed to displace hot air away from the components by creating parallel air flow paths that circulate through the chassis and rack. Air moving systems may take the form of a computer room air conditioning (CRAC) system, a chassis fan system, or fans in an individual node or group of nodes.
As the density of heat generating components increases, air cooling solutions are becoming more prohibitive and costly. In recent years, attention has been directed to cooling high heat flux microprocessor modules. However, with an increase in bandwidth and server throughput, large amounts of on-board memory are also required to achieve increased performance. In order to provide this increase in the amount of memory in servers, computer systems have experienced an increase in the number of standard memory packages, such as dual in-line memory modules (hereinafter DIMMs). In addition, each memory package often has increasing power consumption, increasing heat generation and tighter DIMM row spacing associated with it. Memory modules can contribute as much as 50% of the total server heat load. If the maximum DIMM temperature dictated by reliability is unchanged, then traditional air cooled servers will require greater airflow in order to achieve increased heat removal.
In recent years, direct or indirect liquid cooling has become a more attractive option for the designers of computing systems. Liquid cooled structures have been shown, in some circumstances such as large data centers, to consume less energy. The systems currently in use, however, whether air cooled or water cooled, provide limited options and may not be suitable to adequately cool future generations of computer systems or subsystems, especially when it comes to cooling memory packages such as DIMMs. It can be difficult to allocate sufficient space with a computer server for the additional equipment that is necessary to provide liquid cooling, such as inlet and outlet pipes, conduits, cold plates and the like.